This mainly pertains to people currently on selegiline and or MAOIs. This is pure speculation.
Bitter orange contains the tyramine metabolites N-methyltyramine, octopamine and synephrine, substances similar to epinephrine, which act on the α1 adrenergic receptor to constrict blood vessels and increase blood pressure and heart rate.[11][12]
Earl grey tea is frequently flavored with bergamot, which could be grouped in the family of bitter oranges . N-methyltyramine, octopamine, and synephrine all appear to be metabolized by monoamine oxidase. It is possible, like tyramine, MAO-A is inhibited when ingesting these compounds; if this is true, the effects and duration will greatly be enhanced, possibly opening the door for a hypertensive crisis.
At a glance, it may seem that the content of these substances in a cup of earl grey tea is insignificant, so what's the big deal? It takes less than 20mg of tyramine to cause a hypertensive crisis when gut MAO-A enzymes are inhibited. Likewise, I would expect these metabolites would cause an adverse reaction similar dosages.
Anecdotally, I was taking a dose of selegiline, enough to inhibit MAO-A, and was drinking tons of earl grey tea. I experienced chest pains. No other signs of hypertension though, so there is no knowing if the two were connected in my case.
The question is, does bergamot extract have significant amounts of these compounds? If so, would they amount to enough over several cups to err on the side of caution with an MAOI?
Edited by FW900, 18 September 2014 - 02:11 AM.
